The B-52 had this as well. It was used to augment thrust for takeoff, especially on hot days.

It was as simple as pumping water into the compressor stage, cooling the air after the compressor had heated it. This allowed more fuel to be burned without melting the turbine stage. I think the extra mass of the water (steam) may have helped as well.

This is where the terms "Dry Thrust" and "Wet Thrust" came from.

Looks like spraying water into the engines increases thrust. See: https://www.aircraftnerds.com/2018/08/thrust-augmentation.ht...

Edit: big oversimplification on my part, but I’m not an expert.

Sounds like it works like an intercooler on a turbocharged car engine. It cools the intake charge to increase its density to cram more air into the combustion chamber.